15: Cardiovascular Histology

Question 1

What two systems make up the circulatory system?

Answer 1

Cardiovascular system - heart, arteries, capillaries and veins

Lymphatic system

Question 2

Where is 65% of the body’s blood found?

Answer 2

Peripheral veins

Question 3

Name the three fundamental layers of blood vessels, in order of inner ► outer layer.

Answer 3

Inner = tunica intima

Middle = tunica media

Outer = tunica adventitia

Question 4

What name is given to the single layer of squamous epithelial cells lining the tunica intima of blood vessels?

Answer 4

ENDOthelial cells, or the endothelium

Question 5

What is the tunica media composed of?

Answer 5

Single layer of endothelial cells

Basal lamina

Thin layer of connective tissue

Question 6

What is the tunica media predominantly made up of?

Answer 6

Smooth muscle

Question 7

What is the tunica adventitia made up of?

Answer 7

Connective tissue

Question 8

The very largest arteries in the body are also known as ___ arteries.

Answer 8

elastic

Question 9

Name an elastic artery found in the body.

Answer 9

Aorta

Question 10

Why is the aorta termed an elastic artery?

Answer 10

It has many sheets of elastic fibres which provide elastic recoil

Question 11

In large arteries, the vessles have themselves a blood supply - what is this supply called?

Answer 11

Vasa vasorum

Question 12

You can tell that the vessels are progressing from arteries to veins because the amount of ___ ___ decreases

Answer 12

smooth muscle

Question 13

Capillaries are often composed of just a single layer of ___ cells and a basal lamina.

Answer 13

endothelial

Question 14

What is the name given to cells found at intervals outside the basal lamina of capillaries?

Answer 14

Pericytes

Question 15

What are pericytes?

Answer 15

Connective tissue cells with contractile properties

found at intervals outside the basal lamina of capillaries

Question 16

Name the three types of capillary found in humans.

Answer 16

Continous capillary

Fenestrated capillary

Sinusoidal / discontinuous capillary

Question 17

Continous capillaries are found most / least commonly in the body.

Answer 17

most

Question 18

Why fenestrated capillaries given that name?

Answer 18

Small pores in vessel wall

Question 19

Where are fenestrated capillaries found?

Answer 19

Gut mucosa

Endocrine glands

Kidney glomeruli

Question 20

Sinusoidal capillaries lack a ___ ___.

Answer 20

basal lamina

Question 21

What can pass through the large gaps found in sinusoidal capillaries?

Answer 21

Macromolecules (even some cells)

Question 22

Where are sinusoidal capillaries found?

Answer 22

Liver

Spleen

Bone marrow

Question 23

Which structures, found in veins, are inward extensions of the tunica intima?

Answer 23

Valves

Question 24

Name the three layers of the heart (superficial to deep).

Answer 24

Epicardium (or visceral serous pericardium)

Myocardium

Endocardium

Question 25

How can cardiac muscle cells be differentiated from skeletal muscle cells?

Answer 25

**Cardiac muscle cells** tend to have a **single, central nucleus** (sometimes two) **Skeletal muscle cells** have tons of nuclei clustered to one side of the cell

Question 26

In which cells are **intercalated discs** found? What is their function?

Answer 26

**Cardiac muscle cells** (cardiac myocytes) **Provide adhesion** - allow tension to travel from cell-to-cell during contraction

Question 27

Name three structures found within the intercalated discs of cardiac myocytes.

Answer 27

**Desmosomes** **Adherent junctions** **Gap junctions**

Question 28

The epicardium of the heart has a single layer of flattened epithelium - what is this tissue called?

Answer 28

**Mesothelium**

Question 29

Name the three layers of the **pericardium**

Answer 29

**Fibrous pericardium** **Parietal serous pericardium** **Visceral serous pericardium**

Question 30

What is found in the pericardial cavity, and what function does it serve?

Answer 30

**Pericardial fluid** Provides lubrication for heart movement

Question 31

What is found on the outer part of heart valves?

Answer 31

**Outer endothelial layer** with basal lamina

Question 32

What name is given to the core of dense connective tissue found within heart valves?

Answer 32

**Lamina fibrosa**

Question 33

Which structures anchor the leaflets of the atrioventricular valves to the muscles in the walls of the ventricles? What are these muscles called?

Answer 33

**Chordae tendinae** **Papillary muscles**

Question 34

There are three types of **cardiac myocyte** - what are they called?

Answer 34

**Contractile cells** (99%) **Pacemaker cells** **Conducting cells**

Question 35

Pacemaker cells found in the AV node can be distinguised from other cardiac cells by their ___ appearance.

Answer 35

**pale**

Question 36

The Purkinje fibres are much ___ than other cardiac muscle cells.

Answer 36

**larger**

Question 37

Like pacemaker cells found in the AV node, Purkinje fibres also appear very ___ under the microscope.

Answer 37

**pale**

Question 38

Lymphatic vessels drain tissue fluid and return it to veins - where?

Answer 38

In the base of the neck